Connectograms

[richardbeare]

Hi, I'm finally getting to look at ggforce as a basis for implementing connectograms, as you suggested back in july in response to a ggplot2 query.

The stat_pie structures actually look like they are very close to doing most of what I need to get started.

I'm still finding my way around the package code, so thought I'd make some queries before doing anything to stupid.

My first couple of changes were to look at options for changing direction (clockwise/counter clockwise) and orientation (vertical/horizontal). I can see that radial_trans has an offset option, but can't see a way of setting it from a geom_arc_bar call. Also, is there a direction option hidden away? I had a quick go at adding such options but they interacted with "explode".

Finally, do you know of a way of checking what values (e.g. new dataframe columns) are computed internally by various stat_ without checking the code? I know you have some documentation but I was wondering about a ggplot way.

Finally, I think the only thing missing from the current code to implement connectograms is something giving the midpoint of the arcs. This is needed for links and labels. Looks like it should be easy enough to do, but thought I should check that it isn't already there somewhere.

Thanks